A kelly spinner of the present invention is suitably used in connection with a well drilling rig having a derrick, a drilling platform containing a power driven rotary for supporting and/or rotating a string of drill pipe extending through the rotary and into a well below the drilling platform, a swivel supported by the derrick above the drilling platform, a swivel sub rotatably mounted in the swivel and depending therefrom and a kelly depending from the swivel sub and interconnecting with the drill pipe so that drilling mud can be pumped by a mud pump to the swivel, and thence through the swivel sub and kelly to the string of drill pipe. During drilling operations the drill pipe is rotated by the rotary on the drill floor and, as the well is deepened by rotation of a drill bit attached to the bottom of the drill string, the drill pipe is progressively lowered through the rotary in order that the drill bit may be maintained in bearing contact with the bottom of the well. From time to time it is necessary to add an additional joint of drill pipe to the drill string, for example, because of the depth to which the hole has been drilled, and when this is to be done, it is normally necessary to interrupt rotary drilling operations, support the uppermost joint of the string of drill pipe in the rotary with slips, disconnect the kelly from the string of drill pipe supported by the slips, connect the kelly to a new joint of pipe and then connect the new joint of pipe to the drill pipe supported in the kelly.
The kelly spinner of the present invention is used, for example, during the kelly connecting and disconnecting operations described above.